Ejector mechanism for scraper

ABSTRACT

An ejector mechanism for an elevator scraper bowl that includes a linkage operated by a single hydraulic actuator for initially drawing a floor section rearwardly to expose an opening in the bottom of the scraper bowl followed by the forward movement of an upright ejector plate for discharging material out of the bowl through the aforementioned opening.

'United States Patent [1 1 Hochmann et al.

[ Nov. 4, 1975 EJECTOR MECHANISM FOR SCRAPER [75] Inventors: Eugene Hochmann, Hudson;

Richard C. Breitenstein, Solon, both of Ohio [73] Assignee: General Motors Corporation,

Detroit, Mich.

[22] Filed: Nov. 13, 1974 [21] Appl. No.: 523,210

[52] US. Cl. 37/126 AB; 37/126 AB [51] Int. Cl. E02F 9/28 [58] Field of Search 37/126, 126 AB, 126 AB,

[56] References Cited UNITED STATES PATENTS Low 37/126 AB 2,303,650 12/1942 Low 37/126 AB 3,325,925 6/1967 l-lermiz et a] 37/126 AE 3,739,504 6/1973 Miller 37/126 AE Primary ExaminerStephen C. Pellegrino Attorney, Agent, or Firm-Edward J. Biskup [57] ABSTRACT An ejector mechanism for an elevator scraper bowl that includes a linkage operated by a single hydraulic actuator for initially drawing a floor section rearwardly to expose an opening in the bottom of the scraper bowl followed by the forward movement of an upright ejector plate for discharging material out of the bowl through the aforementioned opening.

3 Claims, 4 Drawing Figures EJECTOR MECHANISM FOR SCRAPER Various forms of ejectors have been utilized for discharging a load from the scraper bowl of an elevating scraper. The most common of the prior used ejector constructions have an ejector plate that is reciprocated from the rear of the bowl towards the cutting blade while a movable section of the floor supporting the load is drawn rearwardly so as to expose an opening through which the material is discharged. In operating the ejector plate and the movable floor section, separate hydraulic actuating cylinders are normally used that act through appropriate linkages to cause the two members to be moved. In addition, a control circuit is required for coordinating the movement of two members so as to realize the most efficient operation of the system.

The present invention is directed to an ejector mechanism of the above described type but differs therefrom in that it utilizes a unique linkage which requires the use of only one hydraulic actuator cylinder for realizing the sequential movement of the ejector plate and the floor section. The ejector nechanism according to this invention is incorporated with a scraper bowl having an open end which is defined by a pair of laterally spaced side walls and a transverse cutting blade extending between the side walls. A fixed floor portion is spaced to the rear of the cutting blade so as to provide an opening in the bottom of the scraper bowl. The ejector mechanism is a part of the scraper bowl and, in the preferred form, includes an upright ejector plate adjacent the rear end of the fixed floor portion and a movable floor section which normally serves to close the opening in the bottom of the scraper bowl. A linkage interconnects the ejector plate with the movable floor section and includes a first lever pivotally connected at one end to the rear of the ejector plate while the other end is pivotally connected to the scraper bowl. A second lever, located rearwardly of the first lever, is pivotally connected at an intermediate point thereof to the scraper bowl while the lower end of the second lever is pivotally connected to the movable floor section. A hydraulic actuator cylinder is provided that has one end supported by the scraper bowl while its other end is connected to the second lever for moving the lower end thereof rearwardly so as to draw the movable floor section and expose the opening in the bottom of the scraper bowl. In addition a lost motion connection is provided for connecting the upper end of the second lever to an intermediate portion of the first lever so that the ejector plate is moved forwardly by the hydraulic actuator cylinder after the movable floor section is drawn rearwardly.

The objects of the present invention are to provide an improved ejector system for an elevating scraper that includes an upright ejector plate and a movable floor section both of which are sequentially movable through a common linkage having a lost motion connection; to provide an improved ejector linkage for an elevating scraper that utilizes a single power actuator for initially drawing a movable floor section rearwardly to expose an opening in the bottom of the scraper bowl to drop a portion of the load and then causes an upright ejector plate to move forwardly for discharging the remaining material through the opening; to provide an improved linkage that incorporates a lost motion connection for coordinating the rearward movement of a movable floor section of an elevator scraper and the forward movement of an ejector plate for unloading material out of a scraper bowl; to provide a scraper bowl of an elevating type scraper with an improved ejector system that consists of a single linkage operated by a single hydraulic cylinder for coordinating the rearward movement of a floor portion and the forward movement of an ejector plate for discharging material from the scraper bowl; and to provide an improved ejector linkage for an elevating type scraper that includes a pair of pivoted levers that are interconnected by a lost motion connection for sequencing the rearward movement of a floor section and the forward movement of the ejector plate for unloading material out of the scraper bowl.

Other objects and advantages of the present invention will be apparent from the following detailed description when taken with the drawings in which:

FIG. 1 is an elevational view showing an elevating scraper incorporating an ejector mechanism made according to the present invention;

FIG. 2 is a partial view of the scraper bowl incorporated with the elevating scraper of FIG. 1 and shows the detailed parts of the ejector mechanism;

FIG. 3 is a view similar to FIG. 2 but shows the various parts of the ejector mechanism in the positions assumed after the hydraulic actuator cylinder is partially contracted during the ejection operation; and

FIG. 4 is a view similar to FIG. 2 but shows the various parts of the ejector mechanism located in the fully extended positions after the hydraulic actuator cylinder is fully contracted to discharge a load out of the scraper bowl.

Referring to the drawings and more particularly FIG. 1 thereof, a rubber-tired twin-engine scraper 10 is shown comprising the usual tractor 12 which is connected to a transportable scraper bowl 14 by a hitch arrangement l6 and a draw bar 18. The draw bar 18 is fixed to a conventional transversely extending torque tube 20 which, at each end, rigidly carries a rearwardly extending pull arm 22. The rearward end of each pull arm 22 is provided with a socket that is pivotally connected to ball member carried on the side of the scraper bowl 14. A hydraulic jack 24 is provided between a bracket 26 fixed to the torque tube 20 and the lower front end of the scraper bowl 14 for raising the latter from a dig-position to a carry-position.

An elevator device 28 is supported in a conventional manner at the open front end of the scraper bowl and serves to raise material into the scraper bowl during a digging operation. The elevator device 28 extends between laterally spaced parallel side walls 29 and 30 of the scraper bowl l4 and has the lower end thereof located above and forwardly of a cutting blade 31. The cutting blade 31 is located at the forward end of the scraper bowl l4 and extends transversely between the side walls 29 and 30 of the bowl and is rigidly connected therewith. In addition, as seen in FIG. 2, a fixed floor portion 32 is spaced rearwardly from the cutting blade 31 and extends transversely between the side walls 29 and 30 and is rigidly connected therewith. Thus, as is conventional in elevating scrapers of this type, an opening is provided in the bottom of the scraper bowl 14 between the cutting blade 31 and the front edge of the floor portion 32 through which the material contained within the scraper bowl can be discharged. 7

In this regard, an ejector mechanism 34 according to the invention is provided in the scraper bowl for ejecting material through the bottom opening in the scraper bowl. More specifically, the ejector mechanism 34 comprises an upright ejector plate 36 and a movable floor section 38 the latter of which normally serves to close the opening in the bottom of the bowl while the elevating scraper is being loaded. The ejector plate 36 extends between the side walls 29 and 30 and serves as a back wall which together with the side walls, the movable floor section, and the fixed floor portion, form the load retaining portion of the scraper bowl. The lower end of the ejector plate 36 pivotally supports a wiper member 40 which is adapted to move forwardly along the upper surface of the floor portion 32 during the ejection operation. Although not shown, the horizontal movement of the wiper member 40 along the upper surface of the floor portion 32 is guided by appropriate channel members or the like secured to the side walls 29 and 30.

The floor section 38 has the front end thereof provided with a striker blade 42 which is connected thereto by a pivotal connection 44 and is held in an upright position by a cam 46 fixed to the side wall of the scraper bowl when the floor section 38 is in the position of FIG. 2. Each side edge of the movable floor section 38 carries a pair of rollers 48 and 50 which are adapted to move within a guide track 52 formed with the associated side wall. This arrangement allows the floor section 38 to be drawn rearwardly from the position shown in FIG. 2 to that shown in FIG. 4 so as to expose the opening in the bottom of the scraper bowl and permit material to be discharged therethrough as will be more fully understood as the description of the invention proceeds.

Both the forward movement of the ejector plate 36 and the rearward movement of the floor section 38 is controlled by a linkage consisting of levers 54 and 56 and a lost motion connection 58. The lever 54 has its upper end connected by a pivotal connection 60 to the frame of the scraper bowl 14 while its lower end is connected by a pivotal connection 62 to a bracket 64 rearwardly extending from and fixed with the ejector plate 36. The lever 56 has an intermediate portion thereof connected by a pivotal connection 66 to the frame of the scraper bowl while its lower end is connected by a pivotal connection 68 to a link 70 which extends forwardly and is connected to the rear end of the floor section by a pivotal connection 72.

The lost motion connection 58 consists of a pair of triangularly shaped members 74 and 76 each of which is provided with a contact surface 78 located in a common vertical plate extending longitudinally of the scraper bowl. The members 74 and 76 are pivotally interconnected by a pivotal connection 80 the center of which is suitably positioned relative to the centers of the pivotal connections 82 and 84 to assume that the contact surfaces 78 move towards each other when the lever 56 is rotated in a counterclockwise direction. Also, the member 76 is connected by a pivotal connection 82 to an intermediate portion of the lever 54 and the member 74 has a portion connected by a pivotal :onnection 84 to the upper end of the lever 56. In addi- :ion, a double-acting hydraulic cylinder 86 has its cylinier end connected by a pivotal connection 88 to the rame of the scraper bowl while the piston end of the :ylinder 86 is connected by a pivotal connection to the ever 56 at a point 90 located substantially midway be- .ween the pivotal connections 66 and 68.

As seen in FIG. 2, the ejector mechanism 34 is in the retracted position with the wiper member 40 of the ejector plate 36 located adjacent the rear edge of the fixed floor portion 32 and the movable floor section 38 located so it closes the opening in the bottom of the scraper bowl. In order to activate the ejector mechanism 34 so the parts thereof move from load-retaining position of FIG. 2 to the ejection position of FIG. 4, pressurized hydraulic fluid is directed to the piston rod end of the hydraulic cylinder 86 causing the latter to contract and rotate the lever 56 in a counterclockwise direction about the pivotal connection 66. As seen in FIG. 2, the initial movement of the lever 56 causes the strike blade 42 to lose contact with the cam 46 and pivot downwardly as the floor section 38 is drawn rearwardly to partially expose the opening in the bottom of the bowl. This results in a portion of the material at the forward end of the bowl dropping out of the partially exposed opening. At the same time, the forward rotational movement of the upper portion of the lever 56 causes the member 74 to rotate counterclockwise about the pivotal connection 84 and the member 76 to rotate clockwise about pivotal connection 82 until the contact surfaces 78 of the two members engage each other to form, in effect, a single member. As the hydraulic cylinder 86 continues contracting towards the position shown in FIG. 4, it will be noted that the lower end of the lever 56 rotates further in a counterclockwise direction about pivotal connection 66 causing the floor section 38 to be drawn further rearwardly fully retracted to completely expose the opening in the bottom of the scraper bowl so that the remaining material above the opening is dropped out of the bowl. Simultaneously, the engaged members 74 and 76 act as a force transmitting member and, due to the continued forward rotational movement of the upper end of lever 56, cause the lever 54 to rotate in a clockwise direction about the pivotal connection 60. Such movement of the lever 54 results in the ejector plate 36 being moved forwardly to the position shown in FIG. 4. Thus, the material located above the floor portion 32 is pushed forwardly and ejected from the bowl through the opening between the cutting blade 31 and the front edge of the floor portion 32.

Accordingly, from the above description of the operation of the invention, it should be apparent that a single hydraulic cylinder 86 serves to move both the ejector plate 36 and the floor section 38. It will be understood, however, that the term -single is intended to encompass one or more hydraulic cylinders located in the substantially same transverse plane and acting on the same lever.

Various changes and modifications can be made in this construction without departing from the spirit of the invention. Such changes and modifications are contem'plated by the inventors and they do not wish to be limited except by the scope of the appended claims.

We claim:

1. An earthmoving self-loading scraper having a tractor connected by a pull yoke to a trailing scraper bowl, said scraper bowl having an open end defined by a pair of laterally spaced side walls and a transverse cutting blade extending between these side walls, a fixed floor located between said side walls and being spaced to the rear of said cutting blade so as to provide an opening in the lower portion of the scraper bowl, an ejector system in the scraper bowl for discharging material through said opening in said lower portion of the scraper bowl, said ejector system comprising an upright ejector plate between the side walls and a movable floor section for closing said opening in said lower portion of the scraper bowl, a linkage interconnecting the ejector plate with said movable floor section for controlling movement thereof, said linkage including a first lever pivotally carried by the scraper bowl and having a portion thereof pivotally connected to the rear of the ejector plate, a second lever located rearwardly of said first lever and having an intermediate portion thereof pivotally connected to said scraper bowl, means pivotally connecting one end of the second lever to the rear of said movable floor section, a power actuator supported by the scraper bowl and connected to said second lever for moving said one end so as to draw the movable floor section rearwardly to expose said opening in the lower portion of the scraper bowl and thereby drop by gravity a portion of the material in the scraper bowl, and lost motion means connecting the second lever to said first lever whereby said ejector plate is moved forwardly by said power actuator after said movable floor is moved rearwardly so that the remaining material in the scraper bowl is discharged through said opening in the lower portion of the scraper bowl.

2. An earthmoving self-loading scraper having a tractor connected by a pull yoke to a trailing scraper bowl, said scraper bowl having an open end defined by a pair of laterally spaced side walls and a transverse cutting blade extending between the side walls, a fixed floor located between said side walls and being spaced to the rear of said cutting blade so as to provide an opening in the lower portion of the scraper bowl, an ejector system in the scraper bowl for discharging material through said opening in said lower portion of the scraper bowl, said ejector system comprising an upright ejector plate between the side walls normally located adjacent the rear end of said fixed floor, a movable floor section for closing said opening in said lower portion of the scraper bowl, a linkage interconnecting the ejector plate with said movable floor section for controlling movement thereof, said linkage including a first lever pivotally connected adjacent one end to the rear of the ejector plate and pivotally connected adjacent the other end to the scraper bowl, a second lever located rearwardly of said first lever and having an intermediate portion thereof pivotally connected to said scraper bowl, means connecting the one end of the second lever to said movable floor section, a power actuator supported by the scraper bowl and connected to said second lever for moving said one end thereof so as to draw the movable floor section rearwardly to expose said opening in the lower portion of the scraper bowl and drop by gravity a portion of the material from the scraper bowl, and lost motion means connecting the other end of the second lever to said first lever for causing said ejector plate to be moved forwardly by said actuator after said movable floor is moved rearwardly so that the remaining material in the scraper bowl is discharged through the opening in the lower portion of the scraper bowl.

3. An earthmoving self-locking scraper having a tractor connected by a pull yoke to a trailing scraper bowl, said scraper bowl having an open end defined by a pair of laterally spaced side walls and a transverse cutting blade extending between these side walls, a fixed floor located between said side walls and being spaced to the rear of said cutting blade so as to provide an opening in the lower portion of the scraper bowl, an ejector system in the scraper bowl for discharging material through said opening in said lower portion of the scraper bowl, said ejector system comprising an upright ejector plate between the side walls normally located adjacent the rear end of said fixed floor, a movable floor section for closing said opening in said lower portion of the scraper bowl, a linkage interconnecting the ejector plate with said movable floor section for controlling movement thereof, said linkage including a first lever, a first pivotal connection for connecting one end of said first lever to the rear of the ejector plate, a second pivotal connection for connecting the other end of the first lever to the scraper bowl, a second lever located rearwardly of said first lever, a third pivotal connection for connecting an intermediate portion of the second lever to said scraper bowl. a fourth pivotal connection including a link for connecting one end of the second lever. to said movable floor section, a double acting hydraulic cylinder having one end supported by the scraper bowl, a fifth pivotal connection for connecting the other end of the hydraulic cylinder to said second lever for moving said one end thereof about the third pivotal connection so as to draw the floor section rearwardly to expose said opening in the lower portion of the scraper bowl and thereby drop by gravity a portion of the material from the scraper bowl, and lost motion means formed by a pair of pivotally interconnected triangular members for connecting the other end of the second lever to said first lever for causing said ejector plate to be moved forwardly by said actuator after said movable floor is moved rearwardly so that the remaining material in the scraper bowl is discharged through the opening in the lower portion of the scraper bowl, said first and second levers being so arranged that a straight line connecting the centers of the first and second pivotal connections will pass between the third and fourth pivotal connections when the ejector plate and the floor section are in retracted positions. 

1. An earthmoving self-loading scraper having a tractor connected by a pull yoke to a trailing scraper bowl, said scraper bowl having an open end defined by a pair of laterally spaced side walls and a transverse cutting blade extending between these side walls, a fixed floor located between said side walls and being spaced to the rear of said cutting blade so as to provide an opening in the lower portion of the scraper bowl, an ejector system in the scraper bowl for discharging material through said opening in said lower portion of the scraper bowl, said ejector system comprising an upright ejector plate between the side walls and a movable floor section for closing said opening in said lower portion of the scraper bowl, a linkage interconnecting the ejector plate with said movable floor section for controlling movement thereof, said linkage including a first lever pivotally carried by the scraper bowl and having a portion thereof pivotally connected to the rear of the ejector plate, a second lever located rearwardly of said first lever and having an intermediate portion thereof pivotally connected to said scraper bowl, means pivotally connecting one end of the second lever to the rear of said movable floor section, a power actuator supported by the scraper bowl and connected to said second lever for moving said one end so as to draw the movable floor section rearwardly to expose said opening in the lower portion of the scraper bowl and thereby drop by gravity a portion of the material in the scraper bowl, and lost motion means connecting the second lever to said first lever whereby said ejEctor plate is moved forwardly by said power actuator after said movable floor is moved rearwardly so that the remaining material in the scraper bowl is discharged through said opening in the lower portion of the scraper bowl.
 2. An earthmoving self-loading scraper having a tractor connected by a pull yoke to a trailing scraper bowl, said scraper bowl having an open end defined by a pair of laterally spaced side walls and a transverse cutting blade extending between the side walls, a fixed floor located between said side walls and being spaced to the rear of said cutting blade so as to provide an opening in the lower portion of the scraper bowl, an ejector system in the scraper bowl for discharging material through said opening in said lower portion of the scraper bowl, said ejector system comprising an upright ejector plate between the side walls normally located adjacent the rear end of said fixed floor, a movable floor section for closing said opening in said lower portion of the scraper bowl, a linkage interconnecting the ejector plate with said movable floor section for controlling movement thereof, said linkage including a first lever pivotally connected adjacent one end to the rear of the ejector plate and pivotally connected adjacent the other end to the scraper bowl, a second lever located rearwardly of said first lever and having an intermediate portion thereof pivotally connected to said scraper bowl, means connecting the one end of the second lever to said movable floor section, a power actuator supported by the scraper bowl and connected to said second lever for moving said one end thereof so as to draw the movable floor section rearwardly to expose said opening in the lower portion of the scraper bowl and drop by gravity a portion of the material from the scraper bowl, and lost motion means connecting the other end of the second lever to said first lever for causing said ejector plate to be moved forwardly by said actuator after said movable floor is moved rearwardly so that the remaining material in the scraper bowl is discharged through the opening in the lower portion of the scraper bowl.
 3. An earthmoving self-locking scraper having a tractor connected by a pull yoke to a trailing scraper bowl, said scraper bowl having an open end defined by a pair of laterally spaced side walls and a transverse cutting blade extending between these side walls, a fixed floor located between said side walls and being spaced to the rear of said cutting blade so as to provide an opening in the lower portion of the scraper bowl, an ejector system in the scraper bowl for discharging material through said opening in said lower portion of the scraper bowl, said ejector system comprising an upright ejector plate between the side walls normally located adjacent the rear end of said fixed floor, a movable floor section for closing said opening in said lower portion of the scraper bowl, a linkage interconnecting the ejector plate with said movable floor section for controlling movement thereof, said linkage including a first lever, a first pivotal connection for connecting one end of said first lever to the rear of the ejector plate, a second pivotal connection for connecting the other end of the first lever to the scraper bowl, a second lever located rearwardly of said first lever, a third pivotal connection for connecting an intermediate portion of the second lever to said scraper bowl, a fourth pivotal connection including a link for connecting one end of the second lever to said movable floor section, a double acting hydraulic cylinder having one end supported by the scraper bowl, a fifth pivotal connection for connecting the other end of the hydraulic cylinder to said second lever for moving said one end thereof about the third pivotal connection so as to draw the floor section rearwardly to expose said opening in the lower portion of the scraper bowl and thereby drop by gravity a portion of the material from the scraper bowl, and lost motion means formed by a pair of pivotAlly interconnected triangular members for connecting the other end of the second lever to said first lever for causing said ejector plate to be moved forwardly by said actuator after said movable floor is moved rearwardly so that the remaining material in the scraper bowl is discharged through the opening in the lower portion of the scraper bowl, said first and second levers being so arranged that a straight line connecting the centers of the first and second pivotal connections will pass between the third and fourth pivotal connections when the ejector plate and the floor section are in retracted positions. 